The goals of this longitudinal study are to identify the nature and size of risk factors for depression in childhood. Approximately 180 offspring of parents with mild or severe unipolar depression and approximately 105 offspring of parents without psychiatric illness are examined at the start of the study and again two years later. The psychiatric and social/adaptive status of the children is assessed at both points. Research aims include identifying genetic and environmental risk factors associated with the onset of depressive disorders in children, identifying preclinical signs of depression, and determining the impact of parental depression on children. Most children are between 6 and 17 years of age at the time of initial assessment; some adolescents over 18 years are included.